Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2023

Commitments and Contingencies Disclosure [Abstract]

Summary of Activities Relating to Company's CARO Liabilities

The following table summarizes activity relating to CARO liabilities (in millions of dollars):

	Year Ended December 31,
	2023		2022			2021
Beginning balance	$	10.1	$	7.2		$	6.7
Liabilities added during the period		—		2.3			—
Liabilities settled during the period		—		(0.1	)		(0.1	)
Accretion expense		0.8		0.7			0.6
Ending balance	$	10.9	$	10.1		$	7.2

Schedule of Changes in Environmental Contingencies

The following table presents the changes in our environmental accrual. We classify the short-term and long-term liabilities within Other accrued liabilities and Long-term liabilities, respectively, on our Consolidated Balance Sheets (in millions of dollars):

	Year Ended December 31,
	2023			2022			2021
Beginning balance	$	17.7		$	16.8		$	18.7
Additional accruals		1.2			3.2			0.1
Less: expenditures		(1.9	)		(2.3	)		(2.0	)
Ending balance	$	17.0		$	17.7		$	16.8